Spark plug and cooling-jacket arrangement



A ril 22 1924.

I c. E. REDDIG SPARK PLUG AND COOLING JACKET ARRANGEMENT Filed Dec. 31 1920 2 Sheets-Sheet l Aprili 22, 1924. 1,491,361 C. E. REDDIG SPARK PLUG AND COOLING JACKET ARRANGEMENT Filed Dec. 31. 1920 2 Sheets-Sheet 2 Patented Apr. 22, 1924.

S FATENF (CHARLES E. REDDIG, QF KEW GARDEN, NEW YORK, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCUEPORATED, OF NEW YORK, N. Y., A CQRI ORATION OF NEW YORK.

SPARK PLUG-AND GQDLING-TACKET Application filed December 31, 1920. Serial No. 434,180. I

To all whom it may concern:

Be it known that 1, CHARLES Esn. RED- DIG, a citizen of the United States, residing at Kew Garden, Long Island, in the county of Queens, State of New York, have invented certain new and useful Improvements in Spark Plug-and Coolin Jacket Arrange.- ments, of which the following is a full, clear, concise, and exact description.

This invention relates to improvements in aircooled internal combustion engines and deals more particularly with a cylinder head which is to be employed in such engines whereby a greater cooling efi'ect is obtained and more enginepower is realized.

The primary object of the invention is to so arrange a cylinder head surface that not only portions thereof are subject to the action of a cooling medium, but that the entire surface is influenced with equal eflicacy by the heat dissi ating means. The construction is such t at no airpockets are formed which would tend to restrict the cooling action.

A further object of the invention is to so cast a cylinder head that that heat generated or evolved during the operation of the engine, which is not carried off by the exhaust gases, is absorbed chiefly by the metal in the cylinder head and after conduction is radiated from the cylinder head surface. A novel contiguous arrangement of the intake and exhaust manifolds within the cylinder head and their position relative to the other workin parts of the cylinder serve to as-' sist in tlie absorption of the engine heat.

More specifically, the invention is concerned with an engine cylinder, having overhead valves, which is so placed within a casing that air can be made to pass through the casing and over the cylinder surface while the engine is in operation. This circulation of air is obtained by means of a rotary exhaust fan actuated by the engine which is so situated relative to the engine casing that it causes a current of air to enter inlet apertures at the top of the casing and to pass downwardly over the engine cylinder. Sincethe combustion chamber, where the heat is most intense, is located in the upper part of the cylinder, the current of air comes into contact with the hottest part ofthe cylinder first. i

One of the principal features of the 'invention resides in so positioning the spark plug in the side of the cylinder head and its enclosing casing, and in so shaping the heat radiating fins adjacent thereto, that the current of air caused by the fan comes in contact with all surfaces of the pin to cool it. By intensifying the cooling of t e plug, its dielectric strength is materially increased preventing short circuits, and its conductors ofier less resistance to the flow of current therethrough, so that the reliability and the life of the plug are increased. Furthermore, this cooling action tends to prevent the portion of the plug within the cylinder from becoming incandescent and causing preignition which would materially cut down the efliciency and life of the engine.

Other objects and advantages of the invention will be set forth in detail in the following specification and particularly pointed out in the claims.

In the accompanying drawin s Fig. 1 is aside elevation o the engine with parts of the engine casing broken away to provide a partial sectional view of the fly wheel and the fly wheel fan used in cooling the engine. This view illustrates the preferred embodiment of my invention employed in connection with a single cylinder gas engine used to actuate a generator in a direct connected electric power set.

Fig. 2 is an enlarged top plan view of the cylinder head'with portions of the rocker arms broken away to show the position of the spark plug.

Fig. 3 is a vertical section of the cylinder head showing the arrangement of intake and exhaust passages constructed in accordance with the invention.

Fig. 4 is a side elevation of the cylinder head showing thefianged surface construction, the diverging ribs on opposite sides of the spark plug and the rocker arm bearing support integral with said ribs.

Fig. 5 1s a view partly 1n side elevation and partly in section of the cylinder head lid I proach the surface of the cylinder proper at right angles to Fig. 4. showing the relative position of the cylinder head and the air inlet apertures in the engine casing and also showin the direction of the air currents between t e cylinder and enclosing casing.

In the drawings an internal combustion engine embodying the invention is shown as directly connected to a motor generator for actuating the same as a generator and to be driven by the electric machine operating as a motor for starting.

It is to be-understood however that the invention is not limited to engines employed in this combination but is of equal utility with all internal combustion engines of the air cooled type.

Similar reference numerals in the several drawings indicate similar parts.

In carrying out the present invention, a gas engine cylinder 6, provided with special flanged surface construction, hereafter to bedescribed, is placed within an engine casing 2 so that currents of cool air can be made to pass through thecasing 2 and over the cylinder surface. An. exhaust fan 5 connected to the engine crank shaft 3 is adapted' todischarge air from its periphery, and in this Way servesto constantly exhaust the air from within the engine casing 2, which air is replaced by cool air entering apertures 4 at'the top of the casin and also.

through an aperture 7 throug which a spark plug 8 is inserted into the cylinder.

Two rocker arms 11 (Fig. 3) are pivoted in a bearing 9 which is mounted upon the top of the engine cylinder head 1 by means of a support 16. These arms serve to operate overhead valves 17 and 18 which are situated adjacent the center the cylinder; and they must, accordingly, be pivoted at a point on the circumference of the upper cylinder surface in order to give them sulficient leverage. In order that a thorough circulation of air may be obtained over that portion of the cylinder head surface which is immediately beneath the rocker arm bearing 9, the support 16 therefor is so constructed that part of the air striking the horizontal surface of the cylinder head 1 will be deflected through an opening 20 beneath the support, as is shown by the arrows in Fig. 5. In order to control the air currents deflected through the rocker arm beal ing 9 to the end that they might more effectively be used to cool this entire area under the bearing 9, the two legs of the bridge 16 are made broader as they ap- (Fig. 5), and are then extended, after a slight divergence (Fig. 4), along the cylinder wall on either side of the spark plug 8 forming heat radiating fins 10. Between these two diverged fins 10 is a third fin 12 which extends longitudinally over the length of the cylinder wall in a direct line neeaeei with the spark plug and then terminates directly beneath the rocker arm bearing 9. The air currents which pass under the rocker arm bearing 9 are so deflected by the'fins 10 and 12 that they come in contact with the entire area above the spark plug 8, with the top and side of spark plug itself and with the bOSs 13 of the cylinder in which the spark plug is situated. The formation of pocketed areas immediately beneath the spark plug is effectively frustrated by the currents of air entering the engine casing 2 by the aperture 2" through which the spark plug 8 protrudes.

To assist in the absorption of the operating heat of the engine, the cylinder head is so cast that the intake manifold 14 andvalve 17 and the exhaust valve 18, both of the overhead type, are provided with ports on the opposite sides of the partition 21 in order that both the gaseous fuel and the exhaust gases may come in close contact with the partition 21 in passing to and from the explosion chamber of the cylinder. Some of the heat of the exhaust gases passes through the exhaust manifold and through the mufller while the remainder is absorbed by the cylinder walls and the metal surrounding the exhaust manifold. That portion of the heat absorbed by the vertical partition 21 is disposed of b radiation into the adjacent chamber 14w ere is serves a useful purpose in vaporizing and pro-heating the moist particles of the incoming oombustible mixture, which strike it at right angles, while the heat absorbed by the metal of the cylinder head is conducted to its surface and absorbed by the air circulated by the rotary fan as has been previously described.

What is claimed is:

1. In an internal combustion engine having overhead valves, a cylinder, an air jacket for said cylinder, means for causing a current of air to pass through the air jacket and over said cylinder surface; a bifurcated rocker arm bearing support on said cylinder, a spark plug in said cylinder in line with said support, and means for cooling said plug, said means comprising longitudinally divergent heat radiating fins on either side of said plug whereby air passing under said support is made to circulate around said plug.

2. In an internal combustion engine having overhead valves, a cylinder, an air jacket surrounding said cylinder; means for causing a current of air to pass through the ing provided with a hole,'through which the air jacket and over the cylinder surface, circulating air currents will have access to a spark plug in the lateral wall of said cylsaid spark plug. 10 inder, means for cooling said plug, said In Witness whereof, I hereunto subscribe 5 means comprisin converging heat radiating y name thls 29th day of December A. D.,

fins adjacent sai plug, a rocker arm bearing 1 2 support spanning said fins, said support be- CHARLES E. REDDIG. 

